Class Solution

java.lang.Object
g0101_0200.s0133_clone_graph.Solution

public class Solution extends java.lang.Object
133 - Clone Graph.

Medium

Given a reference of a node in a connected undirected graph.

Return a deep copy (clone) of the graph.

Each node in the graph contains a value (int) and a list (List[Node]) of its neighbors.

class Node { public int val; public List<Node> neighbors; }

Test case format:

For simplicity, each node’s value is the same as the node’s index (1-indexed). For example, the first node with val == 1, the second node with val == 2, and so on. The graph is represented in the test case using an adjacency list.

An adjacency list is a collection of unordered lists used to represent a finite graph. Each list describes the set of neighbors of a node in the graph.

The given node will always be the first node with val = 1. You must return the copy of the given node as a reference to the cloned graph.

Example 1:

Input: adjList = [[2,4],[1,3],[2,4],[1,3]]

Output: [[2,4],[1,3],[2,4],[1,3]]

Explanation:

 There are 4 nodes in the graph.
 1st node (val = 1)'s neighbors are 2nd node (val = 2) and 4th node (val = 4).
 2nd node (val = 2)'s neighbors are 1st node (val = 1) and 3rd node (val = 3).
 3rd node (val = 3)'s neighbors are 2nd node (val = 2) and 4th node (val = 4).
 4th node (val = 4)'s neighbors are 1st node (val = 1) and 3rd node (val = 3). 

Example 2:

Input: adjList = [[]]

Output: [ []]

Explanation: Note that the input contains one empty list. The graph consists of only one node with val = 1 and it does not have any neighbors.

Example 3:

Input: adjList = []

Output: []

Explanation: This an empty graph, it does not have any nodes.

Example 4:

Input: adjList = [[2],[1]]

Output: [[2],[1]]

Constraints:

  • The number of nodes in the graph is in the range [0, 100].
  • 1 <= Node.val <= 100
  • Node.val is unique for each node.
  • There are no repeated edges and no self-loops in the graph.
  • The Graph is connected and all nodes can be visited starting from the given node.
  • Constructor Summary

    Constructors
    Constructor
    Description
     
  • Method Summary

    Modifier and Type
    Method
    Description
     

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
  • Constructor Details

    • Solution

      public Solution()
  • Method Details

    • cloneGraph

      public Node cloneGraph(Node node)